Cisco Systems, Inc.
Method and system for preventing or correcting fan reverse rotation during online installation and removal

Abstract:

In one embodiment, a method includes detecting reverse rotation of a fan inserted into a modular electronic system comprising at least one other fan, wherein the reverse rotation of the fan is caused by a back pressure generated by the other fan rotating in a forward direction, applying current pulses to stop reverse rotation of the inserted fan and start rotation of the fan in a forward direction, and operating all of the fans with rotation in the forward direction.